人体肝脾血吸虫病的发病机制及其防治研究进展

研究了血吸虫对人体肝脾所致损伤的机理、多因素的发病机制、肝脾硬化导致的循环障碍、矸脾功能代偿失调、肝脾血吸虫病的诊断、预后及其防治难点。     

IRAP: An efficient retrotransposon-based electrophoretic technique for studying genetic variability among geographical isolates of Schistosoma japonicum

In the present study, a inter-retrotransposon-amplified polymorphism (IRAP) technique, based on retrotransposons, was used to examine genetic variability among Schistosoma japonicum isolates from different provinces in mainland China. Of the 15 primers screened, 5 produced highly reproducible IRAP patterns. Using these primers, 54 discernible DNA fragments were generated with 40 (74.07%) being polymorphic, indicating considerable genetic variation among the examined S. japonicum isolates. The primer LTR-11 was found to be able to differentiate male and female parasites, producing one constant specific band for female S. japonicum isolates. The percentages of polymorphic bands (PPB) among all parasites, among isolates from mountainous provinces and among those from the lake/marshland areas were 74.07, 48.15, and 66.67%, respectively. UPGMA analysis revealed that the IRAP profiles could group S. japonicum isolates in mainland China into two clades (mountainous and lake/marshland types), and samples from the same geographical origins clustered together. These results demonstrated that the IRAP technique is suitable for studying genetic diversity and population structures, and also provides an effective technique for studying sex differentiation of S. japonicum.     

一个简单的钉螺控制的数学模型研究

通过建立一个关于单位面积钉螺变化率的数学模型,并对模型中的一些参数分两种不同的情况进行求解.再利用数学软件Mathematic对模型的各种解赋予实际的参考数据进行数值模拟,并对控制措施下的钉螺死亡率k的不同取值,得到相应的模拟图形,根据图形来探讨在不同的控制措施下钉螺数量的变化情况.     

日本血吸虫病肉芽肿的电镜观察

应用长爪沙鼠建立日本血吸虫病动物模型, 观察实验性日本血吸虫病肝脏肉芽肿的超微结构改变. 采用腹部贴片法感染血吸虫尾蚴, 每只沙鼠感染(120±2)条尾蚴, 于5周后解剖, 取出肝脏做病理组织学和透射电镜观察. 结果发现, 肝脏切片H.E.(铁苏木素伊红)染色后可观察到虫卵肉芽肿产生, 透射电镜观察, 可见超微结构改变. 肝脏肉芽肿的超微结构的病变可以清晰地显示肉芽肿的发生机制, 为实验性研究血吸虫病的防治奠定了基础.     

生态血防的范畴和意义

血吸虫病的防治要以生态学和生态工程学的观点和原理来统筹和策划血防工作,解决人类社会和生存环境之间的复杂关系,协调人类和自然环境之间的和谐发展。生态血防是卫生、农业、水利和林业血防的发展。分析了生态血防与灭螺、预防和健康教育的关系,认为从21世纪起,我国将全面进入生态血防阶段,实施以健康教育、封洲禁牧、家畜圈养、切断病源、净化环境、三废入池、发展沼气、农业种植、养殖结构调整和环境工程灭螺为主的综合措施。     

A new group of antischistosomal compounds

A number of compounds containing the 5-nitro-2-thiazolyl group are suitable for the treatment of schistosomiasis; 1-(5-nitro-2-thiazolyl)-2-imidazolidinone is particularly effective. The compounds are taken up selectively by the schistosomes causing the disease and by their eggs, and destroy both. – A review of earlier attempts to control this tropical disease is also presented in this communication.     

Electrophoretic detection of genetic variability among Schistosoma japonicum isolates by sequence-related amplified polymorphism

In the present study, sequence‐related amplification polymorphism (SRAP) was utilized to study the genetic variability among Schistosoma japonicum isolates from different provinces in China, using Schistosoma mansoni from Puerto Rico for comparison. Five out of ten tested SRAP primer combinations displayed significant polymorphisms among S. japonicum isolates from China, namely ME2/EM1, ME4/EM1, ME4/EM6, ME5/EM4 and ME5/EM5. Analysis of the 61 S. japonicum samples from China with five SRAP primer combinations identified a total of 83 reproducible polymorphic fragments. The number of fragments using each primer combination ranged from 14 to 19, with an average of 16 polymorphic bands per primer pair, and the size of fragment ranged approximately from 100 to 1000 bp. Representative‐specific SRAP fragments were excised from the gels, and confirmed by PCR amplification of genomic DNA using primers designed and based on the sequences of these SRAP fragments. Based on SRAP profiles, unweighted pair‐group method with arithmetic averages (UPGMA) dendrogram was constructed. UPGMA clustering algorithm categorized S. japonicum isolates from China into nine clades and two lineages (representing the mountainous and lake/marshland regions). These results indicate the usefulness of the SRAP technique for revealing genetic variability among S. japonicum isolates from China, and the SRAP technique should be applicable to other living organisms.     

三维血吸虫病模型的离散算子数值解法及理论分析

本文基于积分守恒性质,应用离散算子方法,给出了三维血吸虫病模型第一齐次边值问题的离散格式,同时证明了数值解的非负性和有界性,较好地体现了这一问题的实际背景,另外给出了最优L~2模误差估计。     

日本血吸虫病与乙肝病毒感染的关系

目的 :研究日本血吸虫病与乙肝病毒 (HBV)感染间的相互关系。方法 :通过体检、直肠镜、B超等方法诊断慢性 (慢血 )及晚期血吸虫病人 (晚血 ) 2 16例 (慢血 118例 ,晚血 98例 )。所有病人用乙肝血清标志物试剂盒检查血清标志物。结果 :2 2 .2 % (48例 )的病人血清标记物阳性 ,其中慢血 HBV感染率为 14.4% ,晚期血 HBV感染率为 31.6 % ,41～ 5 0岁年龄组 HBV感染率高达 5 0 %。18.1% (39例 )的病人 Hbs Ag阳性。结论 :血吸虫病人 HBV感染率明显高于自然人群。血吸虫病合并肝硬化的病人 HBV感染率明显高于非肝硬化病人。血吸虫病与 HBV感染间的关系在于血吸虫病人免疫机能受损使易感性增高 ,而乙肝病毒又可促进血吸虫病人肝脏纤维化。     

Could we expect new praziquantel derivatives? A meta pharmacometrics/pharmacoinformatics analysis of all antischistosomal praziquantel derivatives found in the literature

Praziquantel (PZQ) is the first line drug for the treatment of human Schistosoma spp. worm infections. However, it suffers from low activity towards immature stages of the worm, and its prolonged use induces resistance/tolerance. During the last 40 years, 263 PZQ analogues have been synthesized and tested against Schistosoma spp. worms, but less than 10% of them showed significant activity. Here, we propose a rationalization of the chemical space of the PZQ derivatives by a ligand-based approach. First, we constructed an in-house database with all PZQ derivatives available in the literature. This analysis shows a high heterogeneity in the data. Fortunately, all studies include PZQ as a reference, permitting the classification of compounds into three classes according to their activities. Models involving ligand-based pharmacophore and logistic regression were performed. Five physicochemical parameters were identified as the best to explain the biological activity. In the end, we proposed new PZQ derivatives with modifications at positions 1 and 7, we analysed them with our models, and we observed that they can be more active than the previously synthesized derivatives. The main goal of this work was to conduct the most valuable meta-pharmacometrics/pharmacoinformatics analysis with all Praziquantel medicinal chemistry data available in the literature.